Thread holder for weft replenishing looms



Nov. 4, 1952 CEDERLUND T 2,616,458

' THREAD HOLDER FOR WEFT REPLENISHING LOOMS Filed Dec. 2'7, 1950 INVENTORS ALBERT CEDERLUND ALEXANDER C. KRUKONIS ATTORNEY Patented Nov. 4, 1952 UNITED STATES PATENT OFFICE THREAD QLD RFOR WEMFTBEBLE ISH- ING LOOMS Albert --Oederlun'd, Worcester, and Alexander C.

' KrukoniaAuburn, Mass., assignors to Crompton r& Knowles Loom Works, Worcester, Mass a .corporation of Mass use t Application December 27, 195,0, Se11ia1 No. 202,874

replenishing loom. All of the weft ends of theibobbins .should be akept taut to prevent breakage .by the play, but because of ;the- -nature of certain fine'yarns itis 'difficultio ma-intain their tension andalso prevent them from pulling away from "the thread holder at the time ofpicking of .a

shuttle freshly replenishedwith such a yarn. It "has:beenproposed-dnthe past to employ meshing gears between "which the weft ends .extend and rotate the-gears by -mechanism of one-form or another in a direction to draw the weft .ends away from the reserve bobbins :tos-tension them. -.When a single @pair of gears -.is employed, however, it is found that :whilez-they may operate satisfactorilyzwith -;the .coarse threads they do not exertsufiicientholdingiorce ortension on the fine threads,;.such-as:,rayon.

It :is an important object of the present invention to provide :a athread holder wherein all .of the weft -.threads i extending from Y the bobbins "inthemagazinearesubjectedrto:an initial or primary :tension :and wherein the threads are then separated into groups according to weft type and each group is .subjected :to .a secondary tension -,adapted to the requirementsof the threads of the group. 1111 carrying this feature of the i in- .vention into 1. effect a. group of fine wefts and a second group-of :coarsewefts. may beledrbetween apair of rotary meshing geared members and -be subjected to a common tension, after which the :group of "line :wefts fWlll be led "to a :secondary tensioningigeared member to be-subjecteditoa'dditional tension suited to fine yarnsandthegroup of coarse threads will beledto another secondary geared member and subjected to additional tension'suited to coarse-yarns. -In some uses of the invention it may not 'be necessary to subject the coarse weft threads to a secondary tension; but it is desirable 'that the fine wefts be subjected tothesecondary:tension.

It-isanother-cbjectof the invention to provide 2 two pairs .of geared tensioning members, .onexfor one type of weft andanother'for a different type of weft, and cause all. of the weft ends to pass between adjacent'meshing gears of the :two pairs.

In this way a single driving mechanism for the tensioning memberstof both pairs will ,suflice to turn all of the .members and subject each group to a primary and also a secondary tension.

In-order to effect-properthreading of ..-a freshly replenished shuttle the thread holder should be in such position thata threadextending from it. to :the shuttle willbe located .f'avorably for such threading and ina position more or less aligned with the shuttle whenthe-latter is picked. -When the weft threads of a multicolor replenishin .mechanism'are divided iI'ItOgtWO groups some provvision should be made forilqcati :iih threads 1 thedifierent groups favorably for shuttle threading. It is :a further-object of the present invent on to pr vide a seared ype thread h lde wherein all of t threadsirom-.-th ;1rese r zh 'rbins are ledrbetween :an i .p z ension n mem- .bers before bein sepa at d :to th secondar :tensioning members. geared membersfi-rst contacting the threads determines theirilocationwhichcan be made :favorn th s wa t pai o able for shuttle threading.

The .sizezof thebundle of threads between the va ious meshing gea ed mem er a stran e 'Qmtime :to mee d t e m mb rs sh d b ,mounted for ibodily rela i m vem n t a mod t th :chanee i bundle site "Th primarymembe rmus h abl t e e at firom each 10121131 1a s suiiicient arnount to accommodate a o the thread but th sec nda mber need move on :ia en u from the ma y members to ac ommo at th i respective r dies of threads. It is ;a;-urther object of the invention ,to,:moun t the various rotary members so that they may mov wh d it espec.t to e other in, accordance with thersizepi the bundles of threads which they -e ng age.

It is .a iurtherzobiectbf the inventio n to hold the movable rotarymembers 1 yielding in position by separate springs which exert separate f orces proportioned to the needs of the thread groups engaged by the members.

It is a still-further object oftthe invention to hanging from the latter members. By this construction rotation of the gears will automatically draw the weft ends to positions where the secondary tension can be exerted on them.

With these and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts hereinafter described and set forth.

In the accompanying drawings, wherein two forms of the invention are set forth,

Fig. 1 is a front elevation of part of a multicolor weft replenishing-loom having the invention applied thereto,

Fig. 2 is an enlarged side elevation looking in the direction of arrow 2, Fig. 1, the bobbins of the various stacks of reserve bobbins being shown diagrammatically,

Figs. 3 and 4 are vertical sections on lines 3--3 and 4-4, respectively, Fig. 2,

Fig. 5 is a vertical section on line 5-5, Fig. 4,

Fig. 6 is a front elevation on a reduced scale looking in the direction of arrow 6, Fig. 2

Fig. '7 is a diagrammatic view showing the relation of the invention to the stacks of bobbins in the magazine and the lay of the loom,

Fig. 8 is a diagrammatic view showing a modified form of the invention, and

Fig. 9 is an enlarged section on line 99, Fig. 2, certain of the parts being omitted.

Referring to Fig 1, the loom frame supports a bottom shaft 2 having secured thereto a cam 3 foroperating a picker shaft 4 connected by sweep stick 5 to a picker stick 6. The loom is provided 'with a lay l which swings backwardly and forwardly in usual manner.

The loom supports a multicolor reserve bobbin magazine M which in the present instance is provided with four stacks m, H, l2 and I3 of reserve bobbins. zine is of the usual stationary type and in the present instance it is assumed that the front The magashuttles is shown at S in Fig. l.

The bobbins await transfer in the magazine and whenever a bobbin of a stack is selected for transfer it will move to transfer position and all thebobbins above it will descend. During this descent the weft ends of the bobbins of the stack from which the selected bobbin has been drawn for transfer will become slack and should be tightened to prevent breakage by the lay. In the present instance the weft ends or threads.

leading from the bobbins BF are indicated at WF while the weft ends or threads leading from the bobbins BC are designated at WC. These weft ends lead to a thread holder designated generally at H supported on an arm I4 secured in any approved manner to a part of the magazine, such as the tie rod l5, which connects the inner and outer bobbin guiding plates l6 and I1, respectively, forming part of the magazine.

Bobbin transfer will ordinarily occur when the lay is approximately midway in its backward motion from front center toward back center and in order to facilitate threading of a freshly replenished shuttle it is desirable that the threads of the transferred bobbins be more or less in line with the lay when the picker stick 6 picks the replenished shuttle. In Fig. 7 the lay is shown in three positions, the position 0!. indicated in dotted lines being the front center position, the intermediate position: shown at .b in full lines 4 being the location of the lay at the time of picking of the replenishing shuttle, and the position 0 shown in dot and dash lines being the back center position. The shuttle will be replenished when the lay is in position a and the shuttle will be picked when the lay is in the position b and will continue in flight across the loom away from the magazine as the lay moves rearwardly to the position 0. Initial self-threading of the shuttle will occur during its flight from the magazine end of the loom. s

The holder H includesin its construction a housing formed with a vertical wall 2| from the left side of which as viewed in Figs 1 and 4 extends a flange 22 which together with wall 2| and cover 23 incloses a compartment 24. Ex-

tending from wall 2| in a direction opposite to the flange 22 is a thread guard 25 having a top 26 and front and back depending sides 27 and 28. The housing is secured to arm M as at 29 and an operating or actuating member, such as rod 30, extends through an opening 3| in the housing to the interior of the compartment 24 for a purpose to be described. This rod may be reciprocated in any approved manner preferably at regularly recurring intervals during loom operation.

The weft ends extending from the reserve bobbins are in the present instance considered to be arranged in two groups, the weft ends from the bobbins BF forming group GI while the weft ends from the bobbins BC form a second group GII. The preferred form of the invention utilizes a series of four rotary weft or thread tensioning members as shown for instance in Fig. 2. These members preferably but not necessarily are made as rigid gears. The forward pair of members comprises an upper gear 35 and a lower gear 36, while the rear pair comprises an upper gear 37 and a lower gear 38. As contemplated herein the upper gear members 35 and 37 are the primary tensioning members while the lower gears 35 and 38 are the secondary tensioning members. All of these members have teeth 39 and j as shown in Fig. 2 in the preferred form the gears are in mesh so that the driving of any gear will drive all the others.

Both of the groups GI and GII of threads pass between the primary gear members 35 and 31, the group GI also passing between primary gear member 35 and its secondary member 36, and group GII passing between the rear upper primary member 3! and the lower secondary member 38. All of the threads of both groups therefore come to a common point between the two primary gears, and then the groups separate from each other and to their respective secondary gears.

The tensioning geared members are located on that side of the wall 2| opposite to the magazine M as shown for instance in Fig. 1. The wall 2| is provided with a bearing 40 to receive a short shaft 4| to one end of which the secondary gear member 38 is secured, as-by a nut 42. The other end of shaft 4| has a ratchet wheel 43 secured thereto, as by a nut 44. The shaft 4|, the gear 38, and the ratchet wheel turn as a unit around fixed axis of the bearing 40.

Rockably mounted on a part of shaft 4| is an actuator lever 45, one end of which is connected as at 46 to the actuator rod 30. A pawl 4'! for the ratchet wheel is pivoted on a stud 48 secured to lever 45. The stud is surrounded by a torsion spring one end 50 of which is connected to the pawl and urges the latter into engagement with the ratchet wheel. The other end-5| of the spring is. connected. to a drum.52 held in angularly adjusted position on the. stud by a set screw 53. The spring yields to permit an idle stroke of the pawl withrespect to theratchet wheel when rod 30 is lifted as viewed. in Fig. 2 and causes the ratchet wheel and gear 38 to turn in the direction of arrow d, Fig. 2, whenthe rod 30 is depressed. The drum affords means for adjusting the force of the spring on the pawl. During loom operation the rod 30 by its reciprocation as. already men.- tioned will give the secondary geared member 38 periodic angular motions to turn: it around a substantially fixed or stationary axis.

The upper rear primary'gear member 37 which meshes with secondary gear member 38 is secured to a shaft 55 rotatable in a hub bearing 55 on a link 57 mounted for rocking motion about a stud 58 fixed withrespect to wall.2l. A. compression spring 60 interposed between link 51 and an. adjusting screw 6| tapped intothe top of the flange 22 urges the primary gear 31 downwardly against the secondary gear 38 but permitsupward motion ofv gear 31 to accommodate a. group of weft ends.

Primary gear 35 which meshes with primarygear 31 is secured to a shaft 55 rotatable in hub bearing 56 of a link 6'! rockable. about a stud 58 secured to wall 2|. A spring 69 and adjusting screw iii similar to spring ti] and screw 6! cooperate to urge the primary gear 35 rearwardly or to the right as viewed in Fig. 2 toward meshing position with respect to the primary gear 31.

The other secondary gear at is secured to and rotates with a shaft '15 turning in a hub bearing 16 on a link 11 pivotally mounted on a stud secured to wall 2i. Spring is and adjusting screw at similar to spring 60 and screw iii cooperate to urge the forward secondary gear member 36 upwardly into meshing position with respect to the top forward primary gear 35.

The gear members 35-3'l are therefore mounted for bodily movement with respect to the gears with which they mesh, each of these gears turning with a short shaft journaled in a link the hub of which passes through a slot 82 in wall 2 i. All of the gear members turn when the pawl has a working stroke with respect to the ratchet wheel.

The secondary gears underhang the primary gears, or project beyond the primary gears in a direction away from wall 2!. This underhanging is represented at 85 in Fig. 4. Whennew bobbins BF are placed in the magazine the weft ends WF will be led over the guard and then down between the primary gear members and will then be drawn forwardly, or to the left as viewed in Fig. 2, so that they can hang over the underhanging part 85 of the fronot secondary gear 3%. It is found that during operation of the loom turning of the primary and secondary gears and 36, respectively, will eventually cause the group G1 to pass between them so that eventually the group GI will hang down from the forward part of thethread holder, as at 81, Fig. 2. Similarly, when new bobbins BC are placed in the rear stacks of the magazine their weft ends WC will be led between the primary geared members and then will be directed rearwardly over the underhanging part of secondary gear 38 and will eventually move between the rear pair of gears and hang as at 88, Fig. 2.

It will thus be seen that all of the weft ends of both groups are subjected to a primary tensioning at a common point located in the space between the. primary gears, and each group thereafter is subj ectedlto. a seco'ndary tensioning when.

reaching the point of mesh between the associated primary and secondary gears; This secondary point at which tension is applied is'spaced from the primary point and each threadin each group will therefore be held at two points against retrograde movement away. from the thread holder and toward the shuttle when" the latter is picked immediately subsequent to weft. replenishment.

The springs 60, 69 and 19 will yield depending upon the'size of the. group or. bunch of yarns engaging the associated geared members. Ordinarily the relative separation of the primary gears will be somewhat larger than the separation of each primary gear with respect to its secondary gear. Each group of weft ends engages agear member mounted for bodily yielding movement to accommodate itself to the size of group or groups of threads which it engages. During operation of the loom driving force will be transmitted from the secondary gear member 38 to the other gear members so that the latter will turn in the direction of the arrows at indicated in Fig. 2. In the preferred form of the invention shown in Fig. 2 the teeth of the secondary gears are shown as being in. position to mesh or engage with each other, but this is not an. essential relationship.

In the modified form: of the invention shown in Fig. 8 a rod 9!) corresponding to rod 3! rocks a lever 9i corresponding to lever to effect rotation of a top rear primary gear member 92 by structure similiar to that already described in connection with the preferred form of the invention. Gear 92 turns about a fixed axis indicated at 93 in Fig. 8v and meshes with another primary gear mounted for bodily movement on a link acted on by spring 96 in a manner similar to that already described. The front lower secondary gear member 9'! meshing with gear 94 is mounted on link 93 acted on by spring 99, while the other or rear secondary gear member ID!) mashing with gear 92 is mounted on a link Hi! acted on by spring I02.

It isnot thought necessary to set forth in detail the mounting structures for the gears shown in. the modified form of the invention, since these mountings will be similar to those already described for the preferred form. It will be noted, however, thatthe secondary members 91 and ID!) are spaced a sumcient distance so that their teeth Hi3 do not mesh as is the case with the preferred form. In other respects, however, the gears may be as already described moreparticularly in connection with Figs. 2; 3 and 4, and both groups of weft ends will pass between the primary gears 52 and 94, after which the forward group GI will pass between gears 94 and 91 and the rear group GII will pass between gears 92 and Hit.

In both forms of the invention it may be desirable to use a separator and guide A, Fig. 2, to prevent each group from becoming engaged with the gear membersfor the other group. Guide A may be made of sheet metal and has a foot iii] secured to the underside of flange 22 as at Ill and an upright plate i i2 havinginclined edges or shoulders 1 i3 and I I4 for'secondary gears 35 and 38, respectively. Extending upwardly from plate H2 is a separator H5 substantially aligned with the. line of mesh of the primary gears. A small foot i it onthe separator is attached as at i ii] to the upper part of housing 20 to brace the top of the separator and guide A.

Whenfreshbobbins'BF are added to the magazineith'eir weft; SIldSi Wl lwill'be led downto the left, Fig. 2, of separator H between the primary gears and then released to fall on shoulder H3 along which they will slide to a position where they can be engaged by the rising teeth on the right side of gear 36 and be moved to a position between gears 35 and 36. The shoulder H3 overlaps the right side of gear 36 as shown in Fig. 2 and requires the group GI of threads to fall across the teeth of the secondary gear. These threads are prevented from falling into the space between plate H2 and gear 36 by a positioning means or pin I H which extends into a groove l l 8 in the outer face of gear 36.

In similar manner the group GII of threads will be passed down to the right of separator I I5, and released, and will eventually be drawn to a position between gears 31 and 38 by the rising teeth on the left, Fig. 2, of the latter gear.

This combined separator and guide can be used with both forms of the invention, the guide A preventing the threads WF for instance from being able to move to a position between the pair of gears for the weft ends WC, and vice versa.

The underhanging of the secondary gears as at 85 with respect to the primary gears permits any thread which leads away from the common point between the primary gears to rest on its secondary gear until the latter in cooperation with its primary gear can automatically draw the thread to the point where it is subjected to the secondary tension. This underhanging as indicated in Fig. 5 is not essential, however, in all forms of the invention, but has been found convenient when automatic placing of the threads between the gears of a pair is desired.

By referring to Fig. '7 it will be seen that both groups are brought to the common point of mesh between the primary gears in a back and forth position in the loom corresponding more or less to the position b of the lay favorable for threading of the shuttle. The groups then separate in their respective directions but the threads of both groups will be held by the primary rotary members in a position favorable for shuttle threading before separating to their respective secondary gears. It will not always be necessary to mainmain the exact relation between the holder H and the lay shown in Fig. '7 but it is desirable that all the weft ends be drawn from a common point on the holder when their corresponding bobbins have been transferred into a shuttle and the latter is picked.

From the foregoing it will be seen that the invention sets forth simple means by which both fine and coarse weft threads can be divided into groups which are subjected to tensioning at spaced points, primary rotary tensioning members being provided to produce a primary or initial tensioning of all the threads at a common or primary point and additional means, such as a secondary tensioning member being provided for each group to subject the latter to a secondary tensioning at points spaced from the primary point. It will not be necessary in all instances to have the coarse threads subjected to the secondary tension, but secondary tensioning will be desirable for fine threads. It will also be seen that all the threads lead from the magazine to a common point of meshing between two gears and the groups then separate to their respective additional tensioning points so that a thread of either group will be correctly placed for selfthreading of a shuttle. It will also be noted that the movable members have separate springs to exert forces as needed for the several groups of threads. It will be further seen that the lower gear members project beyond the upper members and cause the weft ends to move between the primary and secondary members. Also, the guide A directs weft ends to a point where they can be engaged by the rising teeth of the associated secondary gear and be moved automatically to the point where the secondary tension is applied. The secondary gears need not mesh with each other, and either a primary or a secondary gear can be the driven member of the series of gears.

Having thus described the invention it will be seen that changes and modifications of the foregoing specific disclosure may be made without departing from the spirit and scope of the invention.

What is claimed as new is:

1. In a thread holder for a weft replenishing loom having two groups of weft ends extending from reserve bobbins, two pairs of rotary members, one pair for each group, the members turning during loom operation and each pair tensioning the weft ends of the corresponding group, each pair having one of the members thereof cooperating with one of the members of the other pair to tension the weft ends of both groups in addition to the tensioning of each group by the pair of members corresponding thereto.

2. In a thread holder for a weft replenishing loom having two groups of weft ends extending from reserve bobbins, two primary rotary tensioning members between which both groups of weft ends extend, a secondary rotary tensioning member meshing with one of the primary members, one of said groups being also between said one primary and said secondary members, and means rotating said members to tension said weft ends during loom operation.

3. In a thread holder for a weft replenishing loom having fine and coarse weft ends of reserve bobbins arranged in separate groups, one group containing fine weft and the other group containing coarse weft ends, two primary rotary tensioning members between which both of said groups extend, a secondary rotary tensioning member meshing with one of said primary members, said group containing fine weft ends also extending between said one primary member and said secondary member, and means rotating said members to tension said weft ends during operation of the loom.

4. In a thread holder for a weft replenishing loom having two groups of reserve bobbin weft ends, one of said groups containing fine wefts and the other containing coarse wefts, two pairs of meshing thread tensioning rotary members, the group containing the fine weft passing between the members of one pair to be tensioned thereby and the group containing the coarse weft passing between the members of the other pair to be tensioned thereby, one member of one pair meshing with one member of the other pair and the weft ends of both of said groups passing between said one members of the pairs to be tensioned by said one members, and means rotating said members to tension the weft ends during loom operation.

5. In a thread holder for a weft replenishing loom having two groups of reserve bobbin weft ends, one of said groups containing fine wefts and the other containing coarse wefts, two meshing primary rotary weft end tensioning members between which the weft ends of both of said groups pass, a secondary tensioning member meshing with one of said primary members and another secondary 'member meshing with the other primary member, one of said groups passing between said one primary member and the associated secondary member and the other group passing between said other primary member andsaid other secondary member, and means turning said members during loom operation to tension said weft ends.

6. In a thread holder for a weft replenishing loom having two groups of reserve bobbin weft ends, one of said groups containing fine wefts and the other containing coarse wefts, a pair of rotary tensioningmembers turning during loom operation and tensioning the weft ends of both of said groups in a space between said members, and a secondary rotary member meshing with each primary member, one secondary member for each group, each secondary member cooperating with the primary member meshing therewith to tension the weft ends of the corresponding group.

7. In a thread holder for a weft replenishing loom having two groups of reserve bobbin weft ends, one of said groups containing fine wefts and the other containing coarse wefts, a series of meshing rotary tensioning members turning during loom operation and applying a primary tension to both of said groups at a common point and applying additional tension to each group at a secondary point spaced from the primary point.

8. In a thread holder for a weft replenishing loom having two groups of reserve bobbin weft ends, one of said groups containing fine wefts and the other containing coarse wefts, a pair of primary rotary weft tensioning members movable bodily relatively to each other and between which the weft ends of both groups extend, and a secondary member meshing with each primary member mounted for bodily movement relative to the latter, one of said groups being tensioned by one of said secondary members and the corresponding primary member and the other group being tensioned by the other secondary member and the primary member corresponding thereto, and means turning said members during loom operations to tension said weft ends.

9. In a thread holder for a weft replenishing loom having two groups of reserve bobbin weft ends, one of said groups containing fine wefts and the other containing coarse wefts, means subjecting all of the weft ends of both groups to a primary tension at one point, and means subjeetin'g the weft ends of each group to a secondary tension at a point spaced from said one point.

10. In a thread holder for a weft replenishing loom having two groups of reserve bobbin weft ends, one of said groups containing fine wefts and the other containing coarse wefts, means subjecting all of the weft ends of both groups to a primary tension at one point, and additional means cooperating with part of the first named means to subject at least one of said groups of weft ends to a secondary tension at a point spaced from said one point.

11. In a thread holder for a weft replenishing loom having two groups of reserve bobbin weft ends, one of said groups containing fine Wefts and the other containing coarse wefts, means applying a primary tension to all of the threads of both of said groups and holding said threads in a position favorable for the threading of a shuttle replenished by a bobbin corresponding to any of said threads, and additional means to 10 apply a secondary tension to the groups separately at points spaced from said primary point.

12. In a weft replenishing loom'having reserve bobbins from which weft ends extend, two primary rotary members rotating during loom operation between which the weft ends extend exerting a primary tension on the latter, and a secondary rotary member below the primary members rotating during loom operation having a part thereof projecting beyond the primary members and cooperating with one of the latter to exert a secondary tension on the weft ends, a weft end extending from the primary member and falling on said part of the secondary member being moved by the latter toward a position between said one primary and said secondary members.

13. In a weft replenishing loom having reserve bobbins from which weft ends extends, primary tensioning means including a primary rotary member turning during loom operation effective to exert a primary tension on the weft ends, and a secondary rotary member turning during loom operation cooperating with the primary member to exert a secondary tension on a weft end between the primary and secondary members, said secondary member being below and having a part thereof extending beyond the primary member on which a weft end depending from the primary tension means falls, said part tending due to turning of the secondary member to move the weft end toward a position between the primary and secondary members.

14:. In a weft replenishing loom having reserve bobbins from which weft ends extend, two primary meshing gear members between which the weft ends extend, said members turning during loom operation and exerting a primary tension on said weft ends, a secondary gear member meshing with and below and turning with one of said primary members, and a guide for the weft ends effective to direct a weft end depending from said one primary member toward the teeth of the secondary member which are moving toward the teeth of said one primary gear to exert secondary tention on said weft ends.

15. In a weft replenishing loom having reserve bobbins from which weft ends extend, primary tensioning means including a primary rotary gear member turning during loom operation effective to exert a primary tension on the weft ends, and a secondary rotary gear member turning during loom operation meshing with the primary member to exert a secondary tension on the weft end between the primary and secondary members, said secondary member being below the primary member, and a guide for the weft ends effective to direct aweft end depending from the primary member toward the teeth of the secondary member which are moving toward the primary member.

16. The structure set forth in claim 13 in which the guide is provided with a positioning means extending into a groove in the secondary member to prevent the weft end from falling between the latter member and the guide.

17. In a thread holder for two groups of weft ends extending from reserve bobbins in a weft replenishing loom, a series of rotary weft end tensioning gear members rotating during loom operation, each member meshing with at least one other member of the series, said members arranged in two pairs, one for each group of weft ends, each pair having a primary and a secondary member and the primary members 2,616,458 11 12 meshing with each other and the weft ends of REFERENCES CITED both groups passing between and being tensioned The following references are of record in the by the primary members, means mounting the file of this patent: primary members for bodily movement relative to each other, and. means mounting the members 5 UNITED STATES PATENTS of each pair for bodily movement relative to each Number Name Date other, the members of each pair having the weft Re. 19,100 Payne Mar. 6, 1934 ends of the associated group of weft ends between 1,014,844 Northrop Jan. 16, 1912 them and exerting a secondard tension thereon. 2,385,242 Whitin Sept. 18, 1945 ALBERT CEDERLUND. 10 2,387,289 Payne Oct. 23, 1945 ALEXANDER C. KRUKONIS. 2,387,302 Santon Oct. 23, 1945 

